The NCDB contains data on almost _______ million cases of reported cancer diagnoses for the period 1985 through 2007.

• A. 10
• B. 15
• C. 25
• D. 20

Answer: (C)

This question gauges the scale of the NCDB data. The National Cancer Database collects information from a wide network of participating facilities across the United States, covering a large share of new cancer diagnoses. By the period ending in 2007, the database had accumulated data on roughly twenty-five million cancer cases diagnosed since 1985, which is why the option about twenty-five million is the best fit. The smaller figures would underestimate how extensive the registry is, while twenty million is also too low given the established size of the dataset by that time.